1. Field of the Invention
The present invention relates to a test disc and a drive verification method and, more particularly to, those that could well be used in verification of operations of a recordable type optical disc drive.
2. Description of the Related Art
Presently, standardization is going on for a HDDVD (High Definition Digital Versatile Disc), as a recordable optical disc, that uses a laser beam having a blue color wavelength (which is about 405 nm).
HDDVD standards comprise playback-only read only memory (ROM) standards, ReWritable (RW) type standards, and recordable (R) type standards, which are different from each other in terms of types of disc area formats and management information. Further, according to the HDDVD standards, to facilitate reading of disc information in playback, a disc type and book information to be complied with are stored at a plurality of locations. It is to be noted that according to the standards, the disc format is prescribed; however, such drive operations are not prescribed as which information should be read and reflected on operations of a drive in a case where the drive uses information of the prescribed format.
In the standardization of the HDDVD, it has been proposed to verify the operations of an HDDVD drive. It is to be noted that an HDDVD drive which uses a recordable HDDVD needs to undergo the following verifications in each of recording and playback aspects.
(i) Verification 1 of Playback Operation
In verification of a playback operation, first of all, it is important to verify that an HDDVD drive is capable of performing an appropriate playback at any position in a range between an innermost periphery and an outermost periphery of a disc.
Due to its manufacturing processes, the HDDVD is assumed to encounter warping in its disc surface from an inner periphery to an outer periphery of the disc. On the other hand, due to a reduced wavelength of a laser beam, and the like, a tilt between the playback laser beam and the disc surface has a large influence on playback characteristics. Generally, warping of the disc surface increases toward the outer periphery. Therefore, in this case, it is important to verify the playback operations especially in the vicinity of the outer periphery.
It is to be noted that in the recordable HDDVD, it is assumed that user data would be often recorded fully to the outermost periphery of the disc. From this point of view, it is important to verify whether the drive can appropriately perform playback operations in the vicinity of the outermost periphery, where the characteristics are apt to be unstable.
Next, in verification of the playback operations, it is an important factor that the HDDVD drive can appropriately recognize a border.
In the recordable HDDVD, a border is prescribed beforehand as information that indicates delimiting between sessions. By recording the border at a bordering position of a session, a data region on a disc can be divided into a plurality of sessions. In this case, at a position where the sessions are divided, border-out data and border-in data are recorded, and the border-out data contains information indicating that further recording is possible.
For example, if a disc on which a user data region is left unrecorded is removed from the HDDVD drive without being finalized, the border-out data is recorded next to a last recorded position so that an area recorded up to the removal of the disc may provide one session.
If, in this condition, the disc is mounted to the drive again to record information further, next to the border-out data recorded at an end position of this session, the border-in data is recorded to subsequently record user data. In such a manner, the next session is added.
It is to be noted that instead of thus adding the next session, a user can finalize this disc at his will. In this case, in the disc, a terminator is recorded next to the border-out. Accordingly, this disc turns playback-only. That is, by recording the terminator, further recording is prohibited.
It is to be noted that it is possible to contain, in the border-out data, information indicating that further recording is prohibited. For example, if a disc is removed from the HDDVD drive in a condition where there is no free space in a user data region, the border-out data containing information indicating that further recording is prohibited is recorded next to a recording end position of the relevant user data. In this case, this disc is finalized not by a terminator but by the border-out data to provide a playback-only disc.
In such a manner, the HDDVD employs a border as information indicating delimiting of a session. This border divides a mass-capacity HDDVD into a plurality of sessions to improve its utilization efficiency, thus having a large influence on a utility value of the HDDVD. Therefore, in verification of the playback operations, it is important that the HDDVD drive can recognize a border appropriately.
It is to be noted that the border is used not only in an HDDVD but also in existing DVDs. A DVD border is basically used to delimit sessions from each other, so that the information contained in border-out data is always set so as to indicate that further recording is permitted. In a DVD, to terminate a session at a border, it is necessary to record the border-in data next to the border-out data and set data therein to a condition where additional recording is prohibited. Further, in an HDDVD, a border varies in size according to whether it is at an inner periphery, a middle periphery, and an outer periphery of a disc, and therefore a state of the border is non-uniform in the disc.
In such a manner, an HDDVD border and a DVD border are different from each other in terms of whether the disc can be finalized only with the border-out data. Therefore, if an HDDVD drive is of a type for interchangeability between an HDDVD and an existing DVD, confusion may occur especially in a case where border recognition processing is made common to them. Accordingly, in verification of playback operations, it is necessary to verify whether the HDDVD drive can recognize a border of an HDDVD appropriately, distinguishing it from a DVD.
Furthermore, in verification of the playback operations, it is an important verification factor that the HDDVD drive can appropriately recognize a burst cutting region (BCA: Burst Cutting Area) and a system lead-in region.
In an HDDVD, a recording layer is intermittently eliminated in a circumference direction of the disc, thereby allocating a BCA that contains predetermined information to an innermost periphery of the disc. According to the DVD standards, it is prescribed that a BCA need not necessarily be read, so that it is not necessary for the drive to play back the BCA in particular. However, according to the HDDVD standards, it is prescribed to read a BCA always, so that it is necessary for the drive to correctly recognize data contained in the BCA, so that the HDDVD drive needs to verify BCA playback operations. Further, between a BCA and a user data region, a system lead-in region is placed which retains information by using a spiral pit string. Therefore, in playback operation verification, it is important that data retained in the BCA and the system lead-in region can be played back smoothly.
Thus, in this verification 1 of playback operations, an HDDVD drive that handles a recordable HDDVD needs to verify various items. However, in such verification, if a test disc is prepared for each of the items, the number of the test discs increases, which is accompanied by a problem of troublesome work of verification. Further, to manufacture test discs, it is necessary to provide a very ideal disc free of an error in recording mark and recorded information; therefore, to manufacture a plurality of kinds of test discs, a problem occurs that costs and time to be spent increase correspondingly.
(ii) Verification 2 of Playback Operation
Besides the verification items in the above-described verification 1, in verification of playback operations, it is an important verification factor that an HDDVD drive can appropriately recognize whether a drive test zone has been extended.
In a recordable HDDVD, a trial-write region (drive test zone) is set in each of a data lead-in region and a data lead-out region, so that recording laser power is set by using this region, and thereafter user data us recorded.
Among these two drive test zones, the drive test zone in the data lead-out region is positioned on an outer periphery of the disc and so unstable in terms of recording/playback characteristics and can hardly be used in order to set recording laser power; therefore, the drive generally uses only the drive test zone in the data lead-in region to set the recording laser power. However, if files are recorded in an HDDVD repeatedly, it may be assumed that the drive test zone would be exhausted, so that to cope with such a case, according to the HDDVD standards, besides these two drive test zones, another drive test zone can be extended separately. In this case, this drive test zone is extended by as much as a preset capacity at a termination portion of a region in which user data is recorded. Therefore, a capacity to record user data decreases by just that much.
It is to be noted that if the drive test zone is extended, information to that effect is contained as flag information in recording management data (RMD). This RMD is generally recorded in a preset zone (lead-in recording management zone: L-RMZ) in the data lead-in region.
Therefore, in verification of the playback operations, it is an important factor that the HDDVD drive can appropriately recognize whether the drive test zone has been extended. If this recognition is inappropriate, the user data recording capacity is misrecognized to be as it is despite that the drive test zone has been extended to decrease the data capacity, so that user data may possibly be recorded in a region where the drive test zone has been extended.
In addition, in verification of the playback operations, it is an important factor that the HDDVD drive can appropriately acquire the latest RMD.
Since the RMD is information used to manage a disc recording condition, it is updated each time recording is performed and recorded in the L-RMZ. That is, the L-RMD is dissipated each time the RDM is updated. Accordingly, if RDM is updated repeatedly, it is assumed that the L-RMZ may be used up. To address such a situation, according to the HDDVD standards, an RMZ can be added separately from the L-RMZ. In this case, the RMZ can be set not only in a user data recording region but also in a border that is set to a session delimiting position.
It is to be noted that if RMD is updated, the pre-update RMD is invalidated to validate only the post-update RMD. In this case, information about a position of the latest RMD is recorded in an RMD duplication zone which is set in a data lead-in region. Therefore, the position of the latest RMD can be identified not only by a method for tracking back a link over RMD pieces but also from information recorded in the RMD duplication zone.
In such a manner, in a recordable HDDVD, RMD serving as disc management information can be recorded in a data lead-in area which is set at an initial stage but also in a border in a user data region or the user data region by extending a border-recording management zone (B-RMZ) or a user-recording management zone (U-RMZ). Accordingly, for example, even if a drive in which user data is recorded is different from a drive that plays it back, interchangeability between the drives may be lost unless they can recognize the latest RMD accurately. For example, if the drive has set a U-RMZ to an arbitrary position and retained the latest RMD therein, interchangeability between the drives is lost unless this RMD can be recognized by the other drive accurately.
Therefore, in verification of the playback operations, it is an important factor that the HDDVD drive can appropriately recognize the latest RMD. Unless the latest RMD can be recognized appropriately, a disc recording condition cannot be known, so that smooth recording operations cannot be performed. For example, it may be feared that recording would start at an inappropriate position.
Moreover, in verification of the playback operations, it is an important factor that the HDDVD drive can appropriately recognize a border.
As described in the above verification 1 of playback, as in the case of a DVD, borders in an HDDVD are classified into border-out data and border-in data. Among these, the border-out data is capable of recording information indicating whether further recording is permitted or prohibited, in contrast to the case of a DVD. Accordingly, unless it can be recognized appropriately, a trouble occurs that recording may be prohibited despite that recording is permitted or recording is performed mistakenly despite that recording is prohibited. It is to be noted that in the case of recording an RMZ to a border as described above, the RMZ (B-RMZ) is set to the border-in data. Further, in a recordable HDDVD, a border size is different at an inner periphery, a middle periphery, and an outer periphery in a disc, so that a border state in the disc is not uniform. Therefore, the drive needs to read data by appropriately recognizing borders having different sizes from the HDDVD.
Thus, in this verification 2 of playback, an HDDVD drive that handles a recordable HDDVD needs to verify various items. However, in such verification, if a test disc is prepared for each of the items, the number of the test discs increases, which is accompanied by a problem of troublesome work of verification. Further, to manufacture test discs, it is necessary to provide a very ideal disc free of an error in recording mark and recorded information; therefore, to manufacture a plurality of kinds of test discs, a problem occurs that costs and time to be spent increase correspondingly.
(iii) Verification of Recording Operation
In verification of a recording operation, first of all, it is an important factor that data can be recorded at appropriate signal characteristics. Further, it is another important factor that user data and data lead-in data can be recorded appropriately. Furthermore, it is a further important factor that a border and a terminator can be recorded appropriately.